At the 3rd Generation Partnership Project (3GPP), a standards organization for mobile communication, specifications for Evolved Universal Terrestrial Radio Access (E-UTRA) are currently being drawn up. These specifications are the standard for next-generation mobile communications. In E-UTRA, a single-carrier frequency-division multiple access (SC-FDMA) method will be used as an uplink wireless access method. The SC-FDMA method is a wireless access method for transmitting data values using a physical channel, such as a physical random access channel (PRACH).
A wireless communication apparatus that uses the SC-FDMA method performs a discrete Fourier transformation on N data values in the time domain to transform N data values into N discrete Fourier transformation values (hereinafter, referred to as “transformation values”) in the frequency domain. Then, the wireless communication apparatus maps the N transformation values onto subcarriers and transmits, along a physical channel, such as a PRACH, to the outside, data values in the time domain, which is obtained by performing an inverse Fourier transformation process on the mapped transformation values.    Patent Literature 1: International Publication Pamphlet No. WO 2007/91675
However, with the conventional wireless communication apparatus that uses the SC-FDMA method described above, because all of the N discrete Fourier transformation values are calculated using a discrete Fourier transform equation, there is a problem in that the amount of computation becomes enormous when calculating discrete Fourier transformation values. Specifically, if N data values in the time domain are xu,ncs(n) (0≦n<N), the wireless communication apparatus calculates all of the N transformation values X(k) (0≦k<N) by using the discrete Fourier transform equation illustrated below:
                              X          ⁡                      (            k            )                          =                              ∑                          n              =              0                                      N              -              1                                ⁢                                                    X                                  u                  ,                                      n                    cs                                                              ⁡                              (                n                )                                      ⁢                          W              N              nk                                                          (        1        )            
where, WN illustrated in Equation (1) is defined by Equation (2) below:
                              W          M                =                  ⅇ                                    -              j                        ⁢                                          2                ⁢                π                            N                                                          (        2        )            
The number of times multiplications of real numbers performed by using Equation (1) above is given by 4N(N−1), which is an enormous number of times. For example, if a wireless transmission device transmits data values using a PRACH, because N=839, the number of times real number multiplications are performed using Equation (1) above is 4×839×(839−1)=2,812,328, which is an enormous number of times.